Characteristics of environmental conditions affecting the primary production in Matoya Bay, central Japan
1999
Imai, T. (Mie Univ., Tsu (Japan). Faculty of Bioresources) | Tahara, H. | Kawamura, A.
Environmental parameters (water temperature, salinity, transparency, dissolved oxygen content (DO), and concentrations of chlorophyll a, nitrate, nitrite, phosphate and silicate) affecting the primary production were investigated in Matoya Bay, central Japan, from July 1996 to September 1997. Salinity and concentrations of chlorophyll alpha and nitrate showed remarkable seasonal changes in the upper layers while DO and concentrations of nitrite and silicate were in the lower layers. Concentrations of nitrate and silicate, negatively correlated with salinity, were high in the upper layers. Different from the other nutrients, concentrations of nitrate and silicate were strongly influenced by river discharge. It was suggested that nitrite and phosphate were mainly supplied by regeneration from bottom sediment, deducing from that these two nutrients were at higher concentrations in the lower layer during summer when DO was low. Chlorophyll alpha concentration was lower in the inner part of the bay, while those of the nutrients were higher there. Judging from that, the environmental conditions in the inner part of the bay were under strong influence of river discharge from time to time, and the inner part of the bay would not always be a suitable site for aquaculture of oyster and pearl oyster
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